Asymmetrasca Decedens Research Articles

Does weed infestation alter the population density of harmful leafhopper species in second crop maize?

Weed-insect interaction has been studied for decades to determine the role of weeds in insect infestation. This study investigated the impact of weed density on the population density of important leafhopper species (Cicadellidae: Hemiptera) and their egg parasitoid Anagrus atomus (L.) (Hymenoptera: Chalcidoidea) in maize (Zea mays L.) planted as second crop in Şanlıurfa province, Türkiye during 2022 and 2023. Population densities of harmful leafhopper species, i.e., Zyginidia sohrab (Zachvatkin), Empoasca decipiens (Paoli), Asymmetrasca decedens (Paoli), Psammotettix striatus (Linnaeus), and their parasitoid, i.e. A. atomus were monitored by yellow sticky traps (RAL-1016) under weedy and weed-free conditions. Three traps were hung in each experimental unit and the densities of target species were recorded weekly. The population densities of leafhopper species feeding on Sorghum halepense (L.) (Johnsongrass) and the effect of A. atomus on their population density were also determined in weedy treatment. A total 15 maize leaves were taken from both weedy and weed-free treatments, and S. halepense leaf tissues containing leafhopper eggs parasitized by A. atomus were counted weekly. Weed density had non-significant effect on the population density of Z. sohrab during both years. Contrastingly, increasing weed density increased the population density of E. decipiens & A. decedens complex in 2022. Nevertheless, weed density had non-significant effect on the population density of E. decipiens & A. decedens complex during 2023. Weedy treatment recorded higher population density of P. striatus (140 and 100 adults, respectively); however, both weedy and weed-free treatments recorded similar density (125 and 97 adults) during 2023. Weed density proved a significant factor in increasing A. atomus density. A total of 2935 parasitized eggs were recorded from the weedy treatment, whereas 1609 parasitized eggs were recorded from weed-free treatment. Although direct relationship between leafhoppers and weed density remains uncertain, integrated pest management strategies must consider phytophagous insects feeding on weeds at field edges and within fields and the natural enemy complex.

Determination of Population Dynamics of Cicadellidae (Hemiptera) Species and Their Relationship with Climatic Parameters in Organic Cotton Fields in Hatay Province, Türkiye

In this study, population dynamics of leafhopper (Hemiptera: Cicadellidae) species in organic cotton-growing areas of Hatay province were investigated along with their associations with climatic parameters. Weekly sampling using a sweep net (100 sweep net/parcel) identified nine species within the Cicadellidae family. Among these, Asymmetrasca decedens (Paoli) and Empoasca decipiens (Paoli) displayed high population densities throughout the entire vegetation period of cotton, while Zyginidia sohrab (Zatchvakin), Psammotettix striatus (Linnaeus), Orosius orientalis (Matsumura), Anaceratagallia laevis (Ribaut), and Anaceratagallia sinuata (Mulsant & Rey) were present in both vegetative and reproductive phases of cotton, with Z. sohrab reaching significant population levels. Cicadulina bipunctella (Matsumura) and Balclutha hebe (Kirkaldy) were found only during the reproductive phase, yet they achieved considerably high populations. Correlation and regression analyses have shown a moderate to high level of positive correlation between the population development of five leafhopper species and various temperature (°C) parameters (r=0.578-0.790, p

Insights into the Diversity and Population Structure of Predominant Typhlocybinae Species Existing in Vineyards in Greece.

Insects of the subfamily Typhlocybinae (Hemiptera: Cicadellidae) are pests of economically important agricultural and horticultural crops. They damage the plants directly or indirectly by transmitting plant pathogens, resulting in significant yield loss. Several leafhoppers of this subfamily use vines as hosts. Accurate and rapid identification is the key to their successful management. The aim of this study is to determine the Typhlocybinae species that exist in vineyards all over Greece and investigate the relationship between them. For this purpose, yellow sticky traps were placed, morphological and molecular data were collected, and phylogenetic models were analyzed. The mitochondrial marker Cytochrome Oxidase Subunit I (mtCOI) was applied for the DNA and phylogenetic analysis. The combination of morphological and molecular data resulted in identifying the existence of six different species all over Greece: Arboridia adanae, Asymmetrasca decedens, Hebata decipiens, Hebata vitis, Jacobiasca lybica and Zygina rhamni. Forty-eight different haplotypes were found to exist in the different regions of the country.

The Effects of Different Doses of Nitrogen Fertilizer on Population Dynamics of Pests and Natural Enemies in Second Crop Cotton of Aydın Province, TURKEY

Bu çalışma, 2015-2017 yılları arasında, ikinci ürün pamuk üretim sezonunda, Aydın İli Nazilli Pamuk Araştırma Enstitüsü Müdürlüğü deneme arazisinde yürütülmüştür. Çalışmada, farklı azot dozlarının (0, 70, 140 ve 210 kg N ha-1), sokucu-emiciler ve doğal düşmanlar üzerine etkilerinin belirlenmesi amaçlanmıştır. Çalışmada, Özbek 105, Gloria, Julia ve Lydia pamuk çeşitleri kullanılmıştır. Haftalık periyotlarla yapılan zararlı gözlemleri sonucunda; Aphis gossypii Glover (Hemiptera: Aphididae), Empoasca decipiens Paoli + Asymmetrasca decedens (Paoli) (Hemiptera: Cicadellidae), Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), Thrips tabaci Lindeman (Thysanoptera: Thripidae) ve Tetranychus urticae Koch (Acarina: Tetranychidae) türlerinin farklı azot dozlarına ve pamuk çeşitlerine göre popülasyon değişimleri tespit edilmiştir. Uygulanan azot dozu miktarındaki artış, tüm pamuk çeşitlerinde, zararlıların popülasyon yoğunluğunun artmasına neden olmuştur. Predatör türler olarak; Aeolothrips spp. (Thysanoptera: Aeolothripidae), Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), Campylomma diversicornis Reuter (Hemiptera: Miridae), Nabis spp. (Hemiptera: Nabidae), Orius spp. (Hemiptera: Anthocoridae), Adonia variegata (Goeze) (Coleoptera: Coccinellidae), Coccinella septempunctata Linnaeus (Coleoptera: Coccinellidae), Coccinella undecimpunctata Linnaeus (Col.: Coccinellidae) ve Scymnus spp. (Coleoptera: Coccinellidae) tespit edilmiştir. Çalışmadan elde edilen veriler ışığında, gübrelemenin zararlılar ile mücadelede önemi ortaya konulmuştur. Ayrıca, azot dozlarının, önerilen dozlarda (150 kg N ha-1) uygulanması ile zararlı türlerinin popülasyon yoğunluğunun düştüğü ve bu durumun, ekonomik ve ekolojik pamuk üretimine yardımcı olabileceği belirlenmiştir.

Doğu Akdeniz Bölgesi Kiraz Üretim Alanlarında Cicadellidae (Hemiptera) Familyasına Ait Türlerin Belirlenmesi

Kiraz (Prunus avium L.), tüm dünyada ekonomik değeri yüksek bir meyve türüdür ve ülkemizde de geniş alanlarda üretilmektedir. Cicadellidae familyasına bağlı bazı türler kirazda beslenmeleri sırasında bitki dokularını sokup emerek yaptıkları doğrudan zararın yanında, birçok hastalık etmenini taşıyarak yaptıkları dolaylı zararları ile de önemli ekonomik kayıplara sebep olmaktadırlar. Doğu Akdeniz Bölgesi‘nde kiraz yetiştiriciliğinin yapıldığı illerde Cicadellidae familyasına bağlı zararlı türleri belirlemek amacıyla ele alınmış olan bu çalışma 2014-2016 yıllarında Adana (Pozantı), Niğde (Darboğaz) ve Kahramanmaraş (Andırın ve Merkez) illerinde yürütülmüştür. Bahar (Mayıs-Haziran) ve sonbahar (Ekim-Kasım) aylarında olmak üzere yılın iki döneminde yapılan örneklemeler sonucunda ağaç ve yabancı otlardan Cicadellidae familyasının 35 cinsine bağlı 55 tür belirlenmiştir. Bu türlerden 32‘si Deltocephalinae, 18‘i Typhlocybinae, 4‘ü Agallinae ve bir tanesi ise Megophthalminae altfamilyalarına bağlı olup, bu türler içerisinde Psammotettix striatus (Linnaeus) %45,79 oranı ile en yoğun olarak bulunan tür olmuştur. P. provincialis (Ribaut) ikinci tür (%15,26) olarak belirlenirken, diğer türlerden Empoasca sp. ve Asymmetrasca decedens (Paoli) sırasıyla %7,15 ve %6,63 oranları ile bu türleri takip etmişlerdir. Fitoplazma hastalıklarının esas olarak floemde beslenen ve özellikle Deltocephaline altfamilyasına bağlı cicadellidler tarafından taşındığının bilinmesi nedeni ile bu çalışmada kiraz bahçelerinde belirlenmiş olan Deltocephalinae altfamilyasına bağlı türlerin vektör olma potansiyellerinin belirlenmesi konusunda çalışmalar yararlı olacaktır.

First record of the leafhopper Asymmetrasca decedens (Homoptera: Cidadellidae) in mainland Portugal

Asymmetrasca decedens, a polyphagous leafhopper widely distributed in Mediterranean region, is here reported as a new record to mainland Portugal. Heavy infestations of this species have been found associated with peach, apricot and plum orchards, as well as on Alnus glutinosa, in southern of Serra da Gardunha (Beira Interior Region). Typical symptoms, the so-called ‘hopperburn', with leaves turning yellow and curling their edges downwards before drying-out and shedding, were spotted. Both adults and immature forms cause direct injury and the species also has the ability to be a vector of European Stone Fruit Yellows (16RX-B), among other phytoplasmas. External morphological characteristics of A. decedens, illustration of the male genitalia and a brief description of leaf lesions on peach are presented, in order to enable its identification, since it has a great potential for spreading as a pest. Not only A. decedens reveals a significant resistance to conventional insecticides, which may hinder its control, but also it has a vast host range of economically important plants, like ornamental or fruit trees.

Asymmetrasca decedens (Cicadellidae, Typhlocybinae), a natural vector of ‘Candidatus Phytoplasma phoenicium’

Abstract‘Candidatus Phytoplasma phoenicium’ is associated with a lethal disease of almond, peach and nectarine named almond witches'‐broom disease (AlmWB). The disease spread rapidly in Lebanon from coastal areas to elevations exceeding 1200 m, killing over 150,000 trees in a span of two decades. The mode of spread suggested the involvement of efficient vector(s) and Asymmetrasca decedens (Hemiptera, Cicadellidae) was suspected as it is the most abundant leafhopper species present in Lebanese stone fruit orchards. Living A. decedens specimens were collected from fields heavily infested by AlmWB and used in transmission trials on healthy peach almond hybrid GF‐677 and peach GF‐305 seedlings with an inoculation‐access period of 30 days. PCR analysis supported by sequencing showed that A. decedens is a carrier of the phytoplasma, and that the phytoplasma was detected in insect salivary glands and in some inoculated GF‐677 and GF‐305 seedlings. One year post‐inoculation, ‘Ca. P. phoenicium’ was detected in newly emergent leaves of inoculated seedlings. However, the characteristic symptoms of witches'‐broom were not observed. PCR amplified fragments from phytoplasma‐positive seedlings and from A. decedens samples showed 99.9% nucleotide identity in their 16S RNA region and phylogenetic analysis using a neighbour jointing tree confirmed that the phytoplasmas detected in both insects and inoculated seedlings belonged to 16SrIX‐B (D). The present manuscript is the first known report for a leafhopper vector of ‘Ca. P. phoenicium’ and shows that the incubation period of the disease in plants may be longer than 1 year. The importance of phytosanitary control measures, the adoption of a national strategy and regional cooperation in order to contain the further spread of the disease are discussed.

Determination and population fluctuations of Cicadellidae (Hemiptera: Cicadomorpha) species in pomegranate orchards in Aydin Province, Turkey

Many Cicadellidae (Hemiptera: Cicadomorpha) species may reach high populations in fruit orchards. Cicadellids can cause damage not only by sucking plant sap, but also by transmitting detrimental plant pathogens, which may become more important in many cases. It was aimed to determine Cicadellidae species and population fluctuations of common species in pomegranate orchards in Aydin (Nazilli, Karacasu) province in Turkey. Studies were conducted in two pomegranate orchards through 2009-2010. Samplings were done with two yellow sticky traps and by sweep net with 100-sweep-collection on weeds in each orchard. Additionally, cicadellids were collected by shaking one branch of each tree and 20 trees in total in each orchard. Cicadellidae species and their populations were therefore investigated both on trees and weeds in orchards. As a result, 19 cicadellid species were found in orchards. Of these species, Docotettix cornutus Ribaut, Fieberiella anategea Meyer-Arndt, Asymmetrasca decedens (Paoli)+Empoasca decipiens Paoli and Zyginidia pullula (Boheman) were common on the trees and A. decedens (Paoli)+E. decipiens Paoli, Cicadulina bipunctella (Matsumura), Macrosteles quadripunctulatus (Kirschbaum) were common on the weeds in the orchards. Fieberiella anategea and D. cornutus populations reached high levels in JulyNovember on yellow sticky traps in 2009, but remain low during 2010. Asymmetresca decedens + E. decipiens populations reached high levels in May-June and October in 2009 and 2010. On the other hand, Z. pullula population stayed at a very low level in the years 2009 and 2010.

Survey of leafhopper species in almond orchards infected with almond witches'-broom phytoplasma in Lebanon.

Leafhoppers (Hemiptera: Auchenorrhyncha: Cicadellidae) account for more than 80% of all “Auchenorrhynchous” vectors that transmit phytoplasmas. The leafhopper populations in two almond witches'-broom phytoplasma (AlmWB) infected sites: Tanboureet (south of Lebanon) and Bourj El Yahoudieh (north of Lebanon) were surveyed using yellow sticky traps. The survey revealed that the most abundant species was Asymmetrasca decedens, which represented 82.4% of all the leafhoppers sampled. Potential phytoplasma vectors in members of the subfamilies Aphrodinae, Deltocephalinae, and Megophthalminae were present in very low numbers including: Aphrodes makarovi, Cicadulina bipunctella, Euscelidius mundus, Fieberiella macchiae, Allygus theryi, Circulifer haematoceps, Neoaliturus transversalis, and Megophthalmus scabripennis. Allygus theryi (Horváth) (Deltocephalinae) was reported for the first time in Lebanon. Nested PCR analysis and sequencing showed that Asymmetrasca decedens, Empoasca decipiens, Fieberiella macchiae, Euscelidius mundus, Thamnottetix seclusis, Balclutha sp., Lylatina inexpectata, Allygus sp., and Annoplotettix danutae were nine potential carriers of AlmWB phytoplasma. Although the detection of phytoplasmas in an insect does not prove a definite vector relationship, the technique is useful in narrowing the search for potential vectors. The importance of this information for management of AlmWB is discussed.

Specific identification of some female Empoascini (Hemiptera: Cicadellidae), using morphological characters of the ovipositor and isozyme and mtCOI sequence analyses

AbstractWe identified females of six species of leafhoppers (tribe Empoascini),Asymmetrasca decedens(Paoli),Empoasca affinisNast,E. decipiensPaoli,E. pteridis(Dahlbom),E. vitisGöthe, andJacobiasca lybica(Bergevin and Zanon), using morphological characters of the ovipositor and isozyme and mitochondrial COI sequence analyses. Useful traits of the ovipositor are tooth morphology, length of the toothed area, form of sculpturing, and number and position of sensilla on the first and second pair of valves. Among the set of enzyme systems assayed, four putative loci,sod, hk-2, est-3,andest-2,together provided reliable diagnostic characters for single species, pairs of species, and groups of species. Analysis of mtCOI sequences revealed differences between the six species of Empoascini, and the neighbour-joining tree separated them into three distinct groups. Phenetic trees elaborated using Nei’s index and the Kimura two-parameter model clustered the six Empoascini species in similar groups.

Development of a sampling strategy for the leafhopper complex [Asymmetrasca decedens (Paoli) and Empoasca decipiens Paoli] (Hemiptera: Cicadellidae) in cotton

Studies on development of a sampling strategy for the complex species of leafhoppers, Asymmetrasca decedens (Paoli) and Empoasca decipiens Paoli within glabrous cotton Cukurova 1518 were done in Adana province, Turkey during 2003–2005. The nymphs showed aggregated distribution pattern, but adults regularly distributed on cotton plants with different ages. The leafhoppers were aggregated on the lower leaves of plants with 9 main stem node (MSN). As plants grew to 12 MSN, they typically moved upwards away from damaged lower leaves to less damaged leaves in the middle stratum. The best MSN leaf to sample nymphs or adults of the leafhoppers was the 8th from the apex, when plants had 9–15 MSN. The population density of leafhoppers strongly affected the numbers of leaf samples required. Numbers of samples needed to estimate the densities with 3, 5, and 10 nymphs per leaf sample at the 20% precision level in 0.3 ha area were 33, 12, and 3, respectively. Population densities of the leafhoppers were significantly lower in the early morning (0530–0700 or 0730–0800 h) than those found in other times of a day. This study suggests that leafhoppers could be sample in any time of a day after 0800 h, preferably 1800–1900 h, in June–July period in the Mediterranean region.

Damage assessment of the leafhopper complex [Asymmetrasca decedens (Paoli) and Empoasca decipiens Paoli] (Homoptera: Cicadellidae) in cotton

The leafhoppers [Asymmetrasca decedens (Paoli) and Empoasca decipiens Paoli] have only recently become significant pests of cotton in Turkey. Action threshold level (ATL) of this pest complex is uncertain. The effect of leafhoppers on fruit set and development and yields of glabrous varieties, Caroline Queen, Cukurova 1518 and SG 125 was compared under sprayed (at the ATL of ten leafhoppers per leaf) or unsprayed conditions in 2002–2003. Comparisons of sprayed and unsprayed cotton showed that leafhoppers significantly reduced numbers of fruit and yield. Total losses of the fruiting parts (square plus boll) were similar, ranging from 35 to 55% as well as cotton losses varied from 35 to 50%. Numbers of sucking insects (cotton aphid, whitefly and thrips) and also lepidopterian pests (pink bollworm and bollworm) were very low in both years, and they did not affect cotton development. The current regional ATL for the cotton leafhoppers appears to be too high, and it appears that even five leafhoppers per leaf may be sufficient to significantly reduce yields. It is concluded that ATL of the cotton leafhoppers needs to be re-evaluated in cotton fields in Turkey and also other geographic regions which share similar ecological conditions and same leafhopper species.

Asymmetrasca decedensr: a new pest of almond in Spain 1

Asymmetrasca decedens was the most important of three leafhoppers found infesting almond trees in eastern Spain in late summer 1996, causing stunting of the shoots with small curled leaves. Only non‐bearing trees were affected. Although the species has previously been recorded on peach in Spain, this is the first record on almond.

Effects of Residue Type on Persistence and Biological Activity of Foliar Fenpropathrin

Persistence characteristics and biological activity of total and subsurface residues of fenpropathrin applied as an emulsifiable concentrate to tomato and cotton seedlings were studied. Removal of the surface residue by artificial rain permitted a direct estimation of the activity of the subsurface residue. The decay time of the first 50% of fenpropathrin residue on tomato leaves varied with the concentration applied. Decay time was short (2.4 d) at 100 mg (AI)/Iiter to moderate (12 d) at 500 mg (AI)/liter. About 70-90% of the initial deposit existed as surface residue and was responsible for the variable chemical persistence. The half-life of the subsurface residue was 15-16 d for both concentrations. For both adults of a green leafhopper ( Asymmetrasca decedens (Paoli)) and larvae of the Egyptian cotton leafworm ( Spodoptera littoralis (Boisduval)), the toxicity of the subsurface fraction was significantly lower than that of the total residue. A large difference in the LC50 of the two residue types (LC50subsurface/LC50total = 10) suggested that the toxicity of the total residue against green leafhopper adults was due mainly to the surface component. Antifeeding effects of fenpropathrin on S. littoralis larvae appear to account for lower mortality rates of subsurface residue compared with total residue.

Residue analysis of butocarboxim and aldicarb applied in a drip-irrigated peach grove by the HPLC post-column fluorogenic labeling technique

The new high-performance liquid chromatography (HPLC) post-column fluorogenic labeling technique was used for the analysis of residues of butocarboxim, aldicarb and their sulfoxide and sulfone metabolites in peach leaves and fruits. In order to simplify the procedure, the different metabolites were separated by column chromatography during the cleanup process and the residues were determined by HPLC employing an aqueous methanol solvent in the isocratic mode. The limit of detection for the two insecticides was 0.1 μg/g in the leaves and 0.02 μg/g in the fruit. Aldicarb (10% granular formulation) and butocarboxim (50% E.C. diluted 1:5 with water) were applied to the soil in a drip-irrigated peach grove, by placement under one dripper on one side of each tree. The insecticides were taken up by the tree and distributed almost equally on both sides of the tree. The concentration of the insecticides was somewhat lower in the younger leaves. Residue levels of 0.4 to 0.9 μg/g were detected in the fruits at harvest, 10 and 18 days after the last treatment. Based on the results from the field experiment it was concluded that one of the advantages of drip irrigation was that it enabled adequate control of the green leafhopper (Asymmetrasca decedens) throughout the summer with relatively low dosages of systemic insecticides.